Pro Programming

Today we are going to write a C++ program to check Prime number i.e. if a number enter by user is a prime number or not.

We all know what a Prime number is let’s recall quickly:

Prime Number: A number which is divisible by 1 and itself is called Prime number i.e. it do not have any factors. Let’s see how to check Prime numbers in a program.

Logic behind finding prime number:

Start finding the factors of the number from 1.
Count the total number of factors.
If number of factors are 2 then it is a Prime number otherwise not.

Program to check Prime Number:



#include<iostream>
using namespace std;

int main()
{
    int number,count=0;
    cout<<"Enter a number: ";
    cin>>number;
    for(int a=1;a<=number;a++)
    {
        if(number%a==0)
            count++;
    }
    if(count==2)
        cout<<"t"<<number<<" IS A PRIME NUMBER n";
    else
        cout<<"t"<<number<<" IS NOT A PRIME NUMBER n";
    return 0;
}

#include<iostream>

using namespace std;

int main()

{

int number,count=0;

cout<<"Enter a number: ";

cin>>number;

for(int a=1;a<=number;a++)

{

if(number%a==0)

count++;

}

if(count==2)

cout<<"t"<<number<<" IS A PRIME NUMBER n";

else

cout<<"t"<<number<<" IS NOT A PRIME NUMBER n";

return 0;

}

OUTPUT:

Today we are going to write a C++ program to swap two numbers without using any temporary variable, let’s start. There are many ways to swap two numbers without using a Temporary variable.

Here I’ve discussed two methods:

Using ‘+’ and ‘-‘ operators.
Using Bitwise XOR ‘^’.



There is another way to <a href="https://proprogramming.org/program-to-swap-two-numbers-using-call-by-reference/" target="_blank" rel="noopener">swap using call by reference method</a>.

There is another way to <a href="https://proprogramming.org/program-to-swap-two-numbers-using-call-by-reference/" target="_blank" rel="noopener">swap using call by reference method</a>.

So here’s the First Program:

C++ Program to Swap two numbers using ‘+’ ‘-‘ operators.



#include<iostream>
using namespace std;

int main()
{
   int a, b;

   cout<<"Enter two integers to swap\n";
   cout<<"Enter a= ";
   cin>>a;
   cout<<"Enter b= ";
   cin>>b;

   a = a + b;   \\ ex. a=5,b=6  so,  here a = 5+6 = 11
   b = a - b;   \\  b= a-b i.e. b = 11-6 = 5
   a = a - b;   \\  a= a-b i.e. a = 11-5 = 6

   cout<<"\nAfter Swapping\n";
   cout<<"a = "<<a<<"\nb = "<<b;
   return 0;
}

#include<iostream>

using namespace std;

int main()

{

int a, b;

cout<<"Enter two integers to swap\n";

cout<<"Enter a= ";

cin>>a;

cout<<"Enter b= ";

cin>>b;

a = a + b; \\ ex. a=5,b=6 so, here a = 5+6 = 11

b = a - b; \\ b= a-b i.e. b = 11-6 = 5

a = a - b; \\ a= a-b i.e. a = 11-5 = 6

cout<<"\nAfter Swapping\n";

cout<<"a = "<<a<<"\nb = "<<b;

return 0;

}

OUTPUT:

Now let’s discuss the second method i.e. using the Bitwise XOR ‘^’.

C++ Program to Swap two numbers using Bitwise XOR ‘^’



#include<iostream>
using namespace std;

int main()
{
   int a, b;

   cout<<"Enter two integers to swap\n";
   cout<<"Enter a= ";
   cin>>a;
   cout<<"Enter b= ";
   cin>>b;

   a = a ^ b;
   b = a ^ b;
   a = a ^ b;

   cout<<"\nAfter Swapping\n";
   cout<<"a = "<<a<<"\nb = "<<b;
   return 0;
}

#include<iostream>

using namespace std;

int main()

{

int a, b;

cout<<"Enter two integers to swap\n";

cout<<"Enter a= ";

cin>>a;

cout<<"Enter b= ";

cin>>b;

a = a ^ b;

b = a ^ b;

a = a ^ b;

cout<<"\nAfter Swapping\n";

cout<<"a = "<<a<<"\nb = "<<b;

return 0;

}

OUTPUT:

There many other ways in which we can do this like using call by reference etc. I’ve discussed the simplest one hope you like it, please comment if you have any other methods or any improvement for the above codes. Thank you.

C++ Program to check Prime number

Logic behind finding prime number:

Program to check Prime Number:

OUTPUT:

C++ Program to swap two numbers without using temporary variable

C++ Program to Swap two numbers using ‘+’ ‘-‘ operators.

OUTPUT:

C++ Program to Swap two numbers using Bitwise XOR ‘^’

OUTPUT: